1. Field of the Invention
The present invention relates to disk cartridges, and particularly to a disk cartridge which is installed in a disk reproducing apparatus with a disk-like recording medium accommodated therein.
The following disclose disk cartridges which can be installed in a disk apparatus with the disk-like recording medium accommodated therein, Japanese Utility Model Publication No. 3-48780 (reference 1), Japanese Patent Laying-Open No. 3-122880 (reference 2), Japanese Utility Model Publication No. 4-16309 (reference 3), and Japanese Patent Laying-Open No. 64-67781 (reference 4). The reference numerals enclosed in parentheses in the description below are used in the references cited above.
In reference 1, the lid (1) is attached to the magazine frame (2) rotatably and openably, the disk (21) is accommodated in the disk install hole (25) of the magazine frame (2), and the shutter (3) is provided pivotably being abutting on one surface of the disk (21). In reference 2, the shutter with its sectional shape being U-shaped is slidably provided out of the case so that the shutter and the disk are not directly in contact with each other. In reference 3, the circuit board (4) having electronic parts packaged therein is incorporated in the concave portion (20) surrounded with the upper and lower shells (2a, 2b). The ROM (5) having previously written information and the connector (6a) connected to the pin terminal of the ROM through the print interconnection are provided on the circuit board (4). Programs for protecting data recorded in the information recording medium such as the magnetic disk is recorded in the ROM (5). The contact point (7) of the connector (6a) is exposed from the edge surface of the cassette (2) to make connection to the disk drive apparatus. The single shutter (3), having a large U-like sectional shape, is slidably provided on the exterior of the cassette (2) to prevent inferior contact due to foreign matter or dust present on the contact point (7). In order to protect the contact point (7), this shutter (3) covers the head insert hole (16) and the contact point (7) of the connector (6a) when the cassette (2) is not used, and exposes the head insert hole (16) and the connector (6a) when it is used. In reference 4, the outer terminal such as a connector is provided in a different position, where the outer terminal (36) is provided between the head insert window (33) and the side edge of the disk cartridge.
In reference 1, since the shutter (3) is provided just under the disk (21), the shutter (3) may come in contact with the recording surface of the disk (21) to hurt the recording surface when the shutter (3) is opened or closed or when carrying the disk cartridge, possibly resulting in errors in recording and reproducing.
While reference 2 does not have the problem of reference 1, it has a different problem. Because the shutter is exposed, the edge thereof may injure a user's hands, especially if it is made of metal. Moreover, a user can easily open the shutter so that he/she may touch the recording surface of the disk from the head insert hole which may cause errors. Furthermore, the U-shaped shutter may slightly open to form a gap between the shutter and the case where dust may enter to attach on the recording surface of the disk also possibly resulting in errors.
In reference 3, since the contact point (7) of the connector (6a) is provided alongside of the head insert hole (16) along the sliding direction of the shutter (3), and the single shutter (3) opens and closes both the head insert hole and the connector (6a) simultaneously, its lateral width is large. Further, an area corresponding to the lateral width of the connector (6a) must be provided on both sides of the window hole (13) of the shutter (3) so that the lateral width of the shutter (3) increases as the lateral width of the connector (6a) increases. Similarly, the interval between the head insert hole (16) of the cassette (2) and the connector (6a) must increase corresponding to the lateral width of the connector (6a) with the result that the lateral width of the cassette (2) must be increased. Because the electronic circuit part must be provided in the vicinity of the head insert hole and the connecting member in the disk drive apparatus must also be provided in the vicinity of the head insert hole, the location and shapes of the connecting member and the head are limited. When a printed circuit board (10) and the connector (6a) are arranged in a manner that they are lying on top of a disk (1) in the direction of thickness of the cassette (2), the lateral width of the cassette (2) does not increase but the thickness of the cassette (2) must considerably increase. In this case, the rigidity of the cassette (2) must be strengthened. Furthermore, the user may touch the disk or the contact erroneously because he/she can pinch the shutter (3) to open it which may result in a decrease in reliability because of contamination. Also, the shutter opening/closing mechanism of the disk drive apparatus is complex because it is opened and closed in the direction perpendicular to the direction of the insertion of the shutter, resulting in increased cost.
In reference 4, the lateral width covering the head insert window (33) is sufficient for the shutter (34), but the latitudinal width of the accommodation body (32) must be corresponding to the longitudinal width of the outer terminal (36).